The overall objective of this proposal is to elucidate the relative importance of adrenal cholesterol arachidonate (and adrenate) as an important source of the precursor acids for postaglandin synthesis, and to investigate the roles of these prostaglandins, either as intra- or intercellular agents, in modifying or modulating the action of ACTH on adrenal cortical cells. The basic model is the adrenal fascicula cell, prepared from control unstressed rat adrenals, or following various perturbations, including development of Essential Fatty Acid Deficiency in rats.